AND MESOPLODON SOWERBYI. 769 



Doumet, and Van Beneden ; and in the two exotic crania it is more swollen, and 

 projects somewhat higher above the pre-maxillse than in the European skulls. 

 In the Cape cranium, figured by Gray and Owen, it is more mesial and uni- 

 formerly tapering from behind forwards than in the Shetland specimen, and in 

 those described by Doumet and by Fischer. But these are all differences so 

 trifling in degree, as not to exceed that range of individual variation which one 

 often meets with in comparing a seriesof crania of the same species of animal, 

 and which may easily be accounted for by one skull being a little more advanced 

 in its ossification than another. 



In my account of the pre-nasal fossa in the Shetland skull, and of the 

 " septum narium," and its relations to the vomer, I might indeed have adopted 

 almost verbatim the description which Owen has given of these parts in the 

 Cape cranium, so well does it express the arrangement. Similarly, the form 

 and relations of the nasal bones, the configuration of the upper ends of the pre- 

 maxillae and superior maxillae, the form of the palatine surface of the beak, and 

 the relations of the bones which enter into its construction, are identical in all 

 the specimens in which they have been described. 



There can be no doubt, in my opinion, that all these crania, whether exotic or 

 European, should be referred to the genus Ziphius, and in so far I cordially 

 concur with the remarks made by Professor Owen, that there should be " a tacit 

 burial and oblivion" of the ill-defined generic names with which systematic 

 zoology has of late been needlessly and unscientifically encumbered. I also 

 hold that the crania from Fos, Corsica, Arcachon, and Shetland, are specifically 

 identical, and that the " type" of the species is the Ziphius cavirostris of Cuvier. 

 But further, from a comparison of the Shetland cranium with the figures and 

 descriptions of the two specimens from the Cape, I am of opinion that they 

 should not be separated from Cuvier's " type" species by the distinctive name 

 of Ziphius indicus. In recommending a new specific name for his Cape skull, 

 M. Van Beneden appears to have taken Gervais' specimen from Aresquies, in 

 which the meso-rostral bone is absent, as the type of cavirostris rather than 

 Cuvier's original example, in which it is well developed, just as in the crania 

 from Corsica, Arcachon, Shetland, and in Van Beneden's own specimen. He 

 also refers, as another feature of difference, to the absence of teeth in the upper 

 jaw in his specimen, and their presence in the gum of the upper jaw in the 

 Aresquies cranium. But these teeth were quite rudimentary and functionless, 

 and the presence of such aborted organs ought no more to form a basis for 

 establishing a specific difference than should the entire absence of teeth, both 

 in the upper and lower jaw, in the Shetland cranium be a reason for regarding 

 it as a distinct species. Further, there is no evidence that teeth were present 

 in the upper jaw in Cuvier's type-specimen, or in the skulls from Corsica and 

 Arcachon. Moreover, both in Van Beneden's Cape skull and in the one from 



